US4506839A - Forage harvester shear bar with concave cutting surface - Google Patents

Forage harvester shear bar with concave cutting surface Download PDF

Info

Publication number
US4506839A
US4506839A US06/376,082 US37608282A US4506839A US 4506839 A US4506839 A US 4506839A US 37608282 A US37608282 A US 37608282A US 4506839 A US4506839 A US 4506839A
Authority
US
United States
Prior art keywords
shear bar
cutting
cutting surface
cutterhead
harvester
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US06/376,082
Other languages
English (en)
Inventor
Robert D. Black
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Deere and Co
Original Assignee
Deere and Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Deere and Co filed Critical Deere and Co
Priority to US06/376,082 priority Critical patent/US4506839A/en
Assigned to DEERE & COMPANY, A CORP. OF DEL. reassignment DEERE & COMPANY, A CORP. OF DEL. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: BLACK, ROBERT D.
Priority to EP83104058A priority patent/EP0093940B1/de
Priority to AT83104058T priority patent/ATE14500T1/de
Priority to DE8383104058T priority patent/DE3360464D1/de
Priority to CA000427009A priority patent/CA1191352A/en
Application granted granted Critical
Publication of US4506839A publication Critical patent/US4506839A/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C18/00—Disintegrating by knives or other cutting or tearing members which chop material into fragments
    • B02C18/06—Disintegrating by knives or other cutting or tearing members which chop material into fragments with rotating knives
    • B02C18/16—Details
    • B02C18/18—Knives; Mountings thereof
    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01F—PROCESSING OF HARVESTED PRODUCE; HAY OR STRAW PRESSES; DEVICES FOR STORING AGRICULTURAL OR HORTICULTURAL PRODUCE
    • A01F29/00—Cutting apparatus specially adapted for cutting hay, straw or the like
    • A01F29/06—Cutting apparatus specially adapted for cutting hay, straw or the like having rotating knives with their cutting edges on a cylinder surface, e.g. of the helical-type
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
    • B26D—CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING
    • B26D1/00—Cutting through work characterised by the nature or movement of the cutting member or particular materials not otherwise provided for; Apparatus or machines therefor; Cutting members therefor
    • B26D1/01—Cutting through work characterised by the nature or movement of the cutting member or particular materials not otherwise provided for; Apparatus or machines therefor; Cutting members therefor involving a cutting member which does not travel with the work
    • B26D1/12—Cutting through work characterised by the nature or movement of the cutting member or particular materials not otherwise provided for; Apparatus or machines therefor; Cutting members therefor involving a cutting member which does not travel with the work having a cutting member moving about an axis
    • B26D1/25—Cutting through work characterised by the nature or movement of the cutting member or particular materials not otherwise provided for; Apparatus or machines therefor; Cutting members therefor involving a cutting member which does not travel with the work having a cutting member moving about an axis with a non-circular cutting member
    • B26D1/34—Cutting through work characterised by the nature or movement of the cutting member or particular materials not otherwise provided for; Apparatus or machines therefor; Cutting members therefor involving a cutting member which does not travel with the work having a cutting member moving about an axis with a non-circular cutting member moving about an axis parallel to the line of cut
    • B26D1/38—Cutting through work characterised by the nature or movement of the cutting member or particular materials not otherwise provided for; Apparatus or machines therefor; Cutting members therefor involving a cutting member which does not travel with the work having a cutting member moving about an axis with a non-circular cutting member moving about an axis parallel to the line of cut and coacting with a fixed blade or other fixed member
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
    • B26D—CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING
    • B26D7/00—Details of apparatus for cutting, cutting-out, stamping-out, punching, perforating, or severing by means other than cutting
    • B26D7/26—Means for mounting or adjusting the cutting member; Means for adjusting the stroke of the cutting member
    • B26D7/2614—Means for mounting the cutting member
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C18/00—Disintegrating by knives or other cutting or tearing members which chop material into fragments
    • B02C18/06—Disintegrating by knives or other cutting or tearing members which chop material into fragments with rotating knives
    • B02C18/16—Details
    • B02C18/18—Knives; Mountings thereof
    • B02C2018/188—Stationary counter-knives; Mountings thereof

Definitions

  • This invention relates to forage harvesters and more particularly relates to a shear bar for use with a rotary cutterhead.
  • Forage harvesters for removing crop material from the field, reducing the crop material in size and discharging the reduced crop into a collector vehicle are well known.
  • Most currently marketed forage harvesters utilize a cylinder or reel type cutterhead and a stationary shear bar for cutting. Crop material is fed across the upper surface of the shear bar toward the rotating cutterhead which chops the crop into small particles.
  • a cutterhead of this type is disclosed in the U.S. Pat. No. 4,061,284.
  • the shear bar is generally fastened to a strong support structure to insure that the shear bar can withstand the forces encountered during the cutting operation. To eliminate vibration and failure of the shear bar and/or its support, it is important to maintain contact between the shear bar and its support along the entire length of the shear bar.
  • One known method for maintaining such contact is to use a support structure with a curved or crowned upper surface and rectangular shear bar with planar sidewalls. The shear bar is mounted by bending it over the curved support surface into an arched shape thereby providing good contact over the entire length of the shear bar.
  • the arched upper surface is perpendicular to the shear bar surface across which crop material is fed for cutting.
  • an object of this invention to provide an improved forage harvester which has a shear bar which is mounted on a support providing a rigid, vibration free mounting and at the same time is shaped to permit the adjustment of the shear bar at a uniform, precise clearance from the cutterhead thereby improving harvester cutting efficiency and uniformity of cut.
  • a forage harvester comprising a cutterhead rotatable about an axis, having knives supported thereon, and generating a cylinder when rotated about the rotational axis and a shear bar arched such that the upper surface across which crop material is fed is convex and having a cutting surface generally perpendicular to the upper surface.
  • the cutting surface is initially concave toward the cutterhead in a direction parallel to the upper surface prior to being worn by usage in the harvester.
  • the use of an arched shear bar with a concave cutting surface permits the shear bar to be simultaneously rigidly mounted at a uniform clearance from the cutterhead.
  • the shear bar has a second cutting surface opposed to and spaced from the first cutting surface.
  • the second cutting surface is also initially concave away from the first cutting surface prior to being worn by usage in the harvester.
  • the provision of a second cutting surface enables the shear bar to be alternately mounted with the second cutting surface concave toward the cutterhead after the first cutting surface has become worn and is no longer usable. Both longitudinal edges of each cutting surface are also alternately usable as the cutting edge cooperative with the knife edges of the cutterhead.
  • the invention may also be embodied in a method for manufacture of a shear bar wherein a concavity is formed in a cutting surface of the shear bar perpendicular to the upper surface of the shear bar.
  • the plane of the concavity is parallel to the plane of the upper surface.
  • a hardfacing is applied to the cutting surface.
  • FIG. 1 is a fragmentary side elevational view of a forage harvester embodying the invention herein and showing particularly the cutterhead housing with portions of the shielding broken away to show the shear bar.
  • FIG. 2 is a plan view of the shear bar and adjusting mechanism as viewed along line 2--2 of FIG. 1.
  • FIG. 3 is a fragmentary, side elevational view of the shear bar and support taken along line 3--3 of FIG. 2.
  • FIGS. 1 and 2 illustrates the invention embodied in a pull type forage harvester having a mobile main frame 10, only the right rear portion of the harvester being illustrated.
  • pull type harvesters have a generally L-shaped frame.
  • the forward end of the fore and aft of the frame includes a tongue that is attached to a tractor.
  • the frame is support for movement along the ground on a pair of wheels disposed at opposite ends of the rearward transverse portion of the frame.
  • a cutterhead housing 12 is mounted on the outer end of the rearward transverse portion of the frame outboard of the towing tractor.
  • the cutterhead housing includes opposite upright left and right sidewalls 14, 16 respectively, and a generally horizontal top wall 18 extending between opposite sidewalls 14, 16. At the rearward end of the top wall 18 is an upper door 20 spanning the width of the cutterhead housing 12. Upper door 20 is mounted on a transverse hinge 21 which allows door 20 to be swung upwardly to provide access to the interior of housing 12 from the top and rear. Housing 12 also includes a pair of fore and aft, channel-like frame members 22 along the lower portions of sidewalls 14, 16 and a tubular transverse frame member 24 interconnecting frame members 22 between the lower front portion of the sidewalls. Main frame 10 also includes an axle structure 26, generally below housing 12. The right and left wheels are mounted respectively on the axle structure outwardly of and adjacent to the left and right sidewalls 14, 16.
  • a pair of transversely aligned, upper attachment ears 28 extend outwardly from opposite sidewalls 14, 16 at the upper front corner thereof.
  • a similar pair of transversely aligned lower attachment ears 30 project outwardly from opposite sidewalls 14, 16 adjacent to lower forward ends thereof.
  • Various types of harvesting headers are removably mounted on attachment ears 28, 30 and are operative to remove crop material from the field and deliver it rearwardly to the open forward end of the cutterhead housing 12.
  • Upper and lower front feed rolls 32, 33 respectively, are journaled in and extend between left and right sidewalls 14, 16 at the forward end of housing 12.
  • Upper and lower rear feed rolls 34, 35 similarly extend between opposite sidewalls 14, 16.
  • the lower feed rolls 33, 35 are adjacent to one another and are axially fixed.
  • the upper feed rolls 32, 34 are rotatably supported in a mechanism that permits vertical adjustment of the feed rolls 32, 34 to vary the clearance between the respective upper and lower feed rolls according to the thickness of the mat of crop material being fed rearwardly between the two sets of feed rolls.
  • Upper feed rolls 32, 34 rotate in a clockwise direction and viewed in FIG. 1 and lower feed rolls 33, 35 rotate in a counterclockwise direction.
  • Feed rolls 32-35 deliver crop rearwardly over an upper surface 48 of a transverse shear bar 41 that spans the width of the cutterhead housing 12 immediately to the rear of lower feed roll 35.
  • Cutterhead 43 is rotatably mounted in housing 12 about axis a horizontal transverse axis and extends between opposite sidewalls 14, 16. Only the outer periphery of cutterhead 43 is illustrated in FIG. 1 in dotted lines. A preferred cutterhead is disclosed in U.S. Pat. No. 4,061,284, and will not be described in detail herein as the cutterhead forms no part of the invention herein.
  • Cutterhead 43 when rotated about axis X, generates a cylinder with the knife cutting edges at the cutterhead periphery.
  • Cutterhead housing 12 further includes a mechanism (not shown) for sharpening the cutterhead knife edges.
  • a preferred knife sharpener is disclosed in U.S. Pat. No. 4,189,875. A description of the sharpening mechanism has been omitted herein as it forms no part of the invention.
  • Shear bar 41 is supported on cutterhead housing 12 to adjustment toward and away from the cutterhead periphery below a horizontal plane through the axis X to control the clearance between the cutterhead knives and shear bar 41 in a pair of shear bar mounting and adjustment mechanisms 49, 51 connecting the opposite ends of shear bar 41 to opposite sidewalls 14, 16.
  • a preferred embodiment of adjustment mechanism 49, 51 is disclosed in U.S. Pat. No. 4,190,209. A detailed description of the adjusting mechanism 49, 51 is omitted herein as it forms no part of the invention.
  • shear bar 41 includes the upper surface 48, across which crop material is fed for chopping.
  • upper surface 48 is arched upward in a direction perpendicular to the flow of crop material.
  • a first cutting surface 53 and a second, (alternate) cutting surface 55 intersect with upper surface 48.
  • a cutting edge 54 is formed by the intersection of upper surface 48 and the cutting surface 53.
  • An alternate cutting edge 56 is formed by the intersection of surfaces 48, 55.
  • a lower surface 50 may be mounted as the upper shear bar surface across which crop is fed for cutting. In this case, the longitudinal edges formed by the intersections cutting surfaces 53 and 55 with the surface 50 are alternately usable as the cutting edges cooperative with the cutterhead.
  • Shear bar 41 further includes relatively thin layers 65, 67 of a high wear resistant hard facing alloy, such as tungsten carbide, for example, applied in a conventional manner to form cutting surfaces 53, 55, respectively.
  • a preferred process for the application of the tungsten carbide layer is (1) to apply a thin layer of powdered tungsten carbide to the surfaces which are to form cutting surfaces 53, 55 and (2) to heat the shear bar and powder to fuse the tungsten carbide to the shear bar 41.
  • the concavity is machined in the surfaces prior to the application of the tungsten carbide. It will be recognized that the concavity could be formed also after application of the tungsten carbide.
  • the thickness of the hard facing layers 65, 67 is preferably in the range of about 0.01 cm to 0.03 cm.
  • shear bar 41 is supported on support 69 which provides enhanced strength and rigidity for shear bar 41.
  • Support 69 essentially an elongated steel bar having a rectangular cross section, extends between opposite sides 14, 16 of the cutterhead housing 12 and underlies shear bar 41.
  • the opposite ends of both shear bar 41 and support 69 extend through openings 71, 73 in sidewalls 14, 16, respectively. Openings 71,73 are large enough to accommodate fore and aft adjustment of the shear bar on support 69. At least a portion of the edge of the openings 71, 73 is adjacent to support 69 to permit welding of sidewalls 14, 16 to support 69.
  • Support 69 is formed in the shape of an arch and is oriented with the arch extending generally vertical towards the horizontal plane through the axis X.
  • Shear bar 41 is initially formed with planar upper and lower surfaces 48, 50. To further enhance the durability, strength and rigidity of the shear bar, the shear bar 41 is clamped across the support 69 to assume the arched configuration of support 69 by a pair of clamps 75, 77 of adjustment mechanisms 49, 51. To better illustrate the arched configuration of shear bar 41 and support 69 in FIG. 3, a pair of parallel dotted lines 81, 83 are shown adjacent surfaces 48, 50, respectively.
  • cutting surface 53 is initially concave toward said cutterhead prior to being worn by usage of the harvester to chop crop material. It is known that as the shear bar 41 wears the usage, that the cutting surface tends to become concave toward the cutterhead 43. Alternate cutting surface 55 is also initially concave prior to being worn by usage in a harvester. To better illustrate the concave shape of surfaces 53, 55 in FIG. 2, a pair of parallel dotted lines 85, 87 are shown adjacent surfaces 53, 55, respectively. Opposed surfaces 53, 55 are used alternately as the cutting surface against which crop material is cut by cutterhead 43. That is, when the cutting surface 53 is worn so as to be further unusable, the shear bar 41 is removed from the machine and reinstalled so that the surface 55 lies adjacent to cutterhead 43.
  • each cutting surface 53, 55 is machined to form a concavity therein extending in a direction generally parallel to the surface 48 across which crop material is fed for cutting by the cutterhead 43.
  • a powdered layer of tungsten carbide is applied to the surfaces 53, 55 and fused thereon.
  • the hard facing maybe applied prior to forming the concavities.
  • the practice of this invention achieves a shear bar having strength and rigidity to better withstand the cutting forces encountered in chopping of crop material.
  • the shear bar may be accurately adjusted relative to the periphery of the cutterhead 43.
  • the enhanced accuracy of clearance permitted by the formation of a concavity in each cutting surface 53, 55 will reduce the amount of energy required to shear crop material moving across the shear bar and will improve uniformity of crop cutting.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Forests & Forestry (AREA)
  • Mechanical Engineering (AREA)
  • Environmental Sciences (AREA)
  • Food Science & Technology (AREA)
  • Shearing Machines (AREA)
  • Harvester Elements (AREA)
  • Harvesting Machines For Specific Crops (AREA)
  • Crushing And Pulverization Processes (AREA)
  • Threshing Machine Elements (AREA)
US06/376,082 1982-05-07 1982-05-07 Forage harvester shear bar with concave cutting surface Expired - Fee Related US4506839A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US06/376,082 US4506839A (en) 1982-05-07 1982-05-07 Forage harvester shear bar with concave cutting surface
EP83104058A EP0093940B1 (de) 1982-05-07 1983-04-26 Gegenschneide für einen Messerkopf, insbesondere für Erntemaschinen
AT83104058T ATE14500T1 (de) 1982-05-07 1983-04-26 Gegenschneide fuer einen messerkopf, insbesondere fuer erntemaschinen.
DE8383104058T DE3360464D1 (en) 1982-05-07 1983-04-26 Counter knife for a knife head, particularly for harvesting machinery
CA000427009A CA1191352A (en) 1982-05-07 1983-04-29 Forage harvester shear bar with concave cutting surface

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US06/376,082 US4506839A (en) 1982-05-07 1982-05-07 Forage harvester shear bar with concave cutting surface

Publications (1)

Publication Number Publication Date
US4506839A true US4506839A (en) 1985-03-26

Family

ID=23483640

Family Applications (1)

Application Number Title Priority Date Filing Date
US06/376,082 Expired - Fee Related US4506839A (en) 1982-05-07 1982-05-07 Forage harvester shear bar with concave cutting surface

Country Status (5)

Country Link
US (1) US4506839A (de)
EP (1) EP0093940B1 (de)
AT (1) ATE14500T1 (de)
CA (1) CA1191352A (de)
DE (1) DE3360464D1 (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4678130A (en) * 1985-10-04 1987-07-07 New Holland Inc. Quick adjust shearbar mechanism
US4756068A (en) * 1987-04-13 1988-07-12 New Holland Inc. Shearbar attachment and adjustment apparatus and method
US6659378B2 (en) * 2002-03-13 2003-12-09 Guiseppe Di Anna Field shredder for pruned branches
US8109176B1 (en) * 2010-04-14 2012-02-07 Kooima Company Cutting elements with serrated cutting edge
US10251342B2 (en) * 2016-11-01 2019-04-09 Indústrias Reunidas Colombo Ltda Chopping module having box-shaped body, rollers, shearbar, and rotating blade assembly
US11044852B2 (en) 2019-05-21 2021-06-29 Kooima Ag, Inc. Agricultural knife with primary and secondary serrations

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ATE122845T1 (de) * 1992-03-23 1995-06-15 Claas Saulgau Gmbh Gegenschneide für feldhäcksler.

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2870967A (en) * 1955-07-22 1959-01-27 Hansen Lynn Co Inc Dispenser
US4190209A (en) * 1978-07-03 1980-02-26 Deere & Company Adjustable shear bar for a harvester cutterhead
US4298170A (en) * 1977-11-21 1981-11-03 Sperry Corporation Shear bar for forage harvesters or the like

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3342231A (en) * 1965-08-03 1967-09-19 Sperry Rand Corp Forage harvester
US3805660A (en) * 1973-01-15 1974-04-23 Gehl Co Shear bar for forage harvesters or the like
US4061284A (en) * 1976-09-14 1977-12-06 Deere & Company Harvester cutterhead

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2870967A (en) * 1955-07-22 1959-01-27 Hansen Lynn Co Inc Dispenser
US4298170A (en) * 1977-11-21 1981-11-03 Sperry Corporation Shear bar for forage harvesters or the like
US4190209A (en) * 1978-07-03 1980-02-26 Deere & Company Adjustable shear bar for a harvester cutterhead

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4678130A (en) * 1985-10-04 1987-07-07 New Holland Inc. Quick adjust shearbar mechanism
US4756068A (en) * 1987-04-13 1988-07-12 New Holland Inc. Shearbar attachment and adjustment apparatus and method
EP0287159A1 (de) * 1987-04-13 1988-10-19 FORD NEW HOLLAND, INC. (a Delaware corp.) Feldhäcksler
US6659378B2 (en) * 2002-03-13 2003-12-09 Guiseppe Di Anna Field shredder for pruned branches
US8109176B1 (en) * 2010-04-14 2012-02-07 Kooima Company Cutting elements with serrated cutting edge
US10251342B2 (en) * 2016-11-01 2019-04-09 Indústrias Reunidas Colombo Ltda Chopping module having box-shaped body, rollers, shearbar, and rotating blade assembly
US11044852B2 (en) 2019-05-21 2021-06-29 Kooima Ag, Inc. Agricultural knife with primary and secondary serrations

Also Published As

Publication number Publication date
ATE14500T1 (de) 1985-08-15
EP0093940A1 (de) 1983-11-16
EP0093940B1 (de) 1985-07-31
DE3360464D1 (en) 1985-09-05
CA1191352A (en) 1985-08-06

Similar Documents

Publication Publication Date Title
US3635271A (en) Cutterhead and shear bar for forage harvesters
US3805660A (en) Shear bar for forage harvesters or the like
SU978711A3 (ru) Косилка-измельчитель
CA1056279A (en) Harvester cutterhead
US7631479B2 (en) Adjustable pivot axis for bedknife assembly
US4506839A (en) Forage harvester shear bar with concave cutting surface
CA2866594A1 (en) Laser clad cutting edge for agricultural cutting components
US4383652A (en) Shredbar apparatus
CA1125035A (en) Crop harvesting machine
US3974970A (en) Forage harvester cutterhead
US5779167A (en) Forage harvester knife and mounting apparatus
US20190126283A1 (en) Rotary reducing component
US5913724A (en) Combine harvester
EP0022053A1 (de) Gegenschneide mit eingekerbter Schnittkante
US4298170A (en) Shear bar for forage harvesters or the like
US4267690A (en) Disc reel mower and method and means of manufacturing the same
EP0789994B1 (de) Messertrommel eines Feldhäckslers und Montagevorrichtung
GB2071477A (en) Oscillating knife cutter
US3963183A (en) Resharpenable recutter screen for forage harvester
US4312481A (en) Cutterhead crop redirectors
CZ326296A3 (en) Disk-type mowing machine
US4186889A (en) Forage harvester recutter screen
US3752411A (en) Forage harvester
EP4381931A1 (de) Landwirtschaftlicher scheibenmäher mit vollständig umkehrbarem messer
US6112825A (en) Mounting system for cutting head

Legal Events

Date Code Title Description
AS Assignment

Owner name: DEERE & COMPANY, MOLINE, ILL. A CORP. OF DEL.

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:BLACK, ROBERT D.;REEL/FRAME:003994/0806

Effective date: 19820503

FPAY Fee payment

Year of fee payment: 4

REMI Maintenance fee reminder mailed
LAPS Lapse for failure to pay maintenance fees
FP Lapsed due to failure to pay maintenance fee

Effective date: 19930328

STCH Information on status: patent discontinuation

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362